Polyurethane dispersants

ABSTRACT

The present invention provides a non-aqueous composition containing a particulate solid, an organic medium and a polyurethane dispersant having an essentially linear backbone and laterally attached solvent-solubilizing side chains of a polyester, a polyether, a polyacrylate or a polyolefin including mixtures of such side chains.

CROSS REFERENCE

This application is a divisional application of prior U.S. applicationSer. No. 10/556,697 filed on Oct. 10, 2006 which claims priority fromPCT Application Serial No. PCT/US2004/014790 filed on May 11, 2004,which claims the benefit of Great Britain Patent Application No.0311121.8 filed on May 15, 2003.

FIELD OF INVENTION

The present invention relates to polyurethane dispersants, todispersions, millbases, paints and inks containing a particulate soliddispersed in a non-aqueous organic medium, particularly a polar organicmedium, including inks for use in non-contact printing processes such as“Drop-on-demand” printing process. In particular, the dispersantsexhibit an essentially linear backbone with laterally attachedside-chains of solvent solubilizing polyester, polyacrylic, polyether orpolyolefin side chains including mixtures of such side chains.

BACKGROUND OF THE INVENTION

A polyurethane containing polyoxyethylene side-chains is known and hasbeen described in the patent literature. For example, EP 060,430discloses a process for making a polyurethane having polyalkylene oxideside-chains characterised in that the polyalkylene oxide used asstarting alcohol has at least two free hydroxyl groups separated by notmore than 3 carbon atoms, which hydroxy groups react with diisocyanates.The polyurethane may be used to stabilise or destabilise foams,emulsions and dispersions. They may also be used with pigments andfillers. However, there is no mention that the polyurethane may be usedas dispersants in non-aqueous media and especially in the preparation ofnon-aqueous millbases, paints and inks.

JP1995179801 A discloses a water soluble acrylic graft copolymer with apolyurethane backbone. The grafted copolymer has carboxylic acidfunctional groups that may be incorporated into the backbone or withinthe grafted acrylic portion.

SUMMARY OF THE INVENTION

According to the invention there is provided a non-aqueous compositioncomprising a particulate solid, an organic medium and a polyurethanedispersant having an essentially linear backbone with laterally attachedsolvent-solubilizing side chains of polyester, polyacrylic, polyether orpolyolefin including mixtures of such side chains.

DETAILED DESCRIPTION OF THE INVENTION

According to the invention there is provided a non-aqueous compositioncomprising a particulate solid, an organic medium and a polyurethanedispersant having an essentially linear backbone with laterally attachedsolvent-solubilizing side chains of polyester, polyacrylic (especially apolyacrylate), polyether or polyolefin including mixtures of such sidechains. The optimum choice of the solvent solubilising side chain willbe dependent on the polarity of the organic medium. In one embodimentthe polyolefin is present and in another embodiment the polyolefin isabsent.

In one embodiment the non-aqueous composition optionally contains 5 wtor less water, preferably less than 2 wt %, more preferably less than0.5 wt. % and most preferably no water.

Whereas the polyester, polyether, polyacrylate or polyolefin side chainsmay contain a terminating hydroxy group remote from the polyurethanebackbone it is much preferred that such chains carry a [terminating]group which is not reactive with isocyanates and especially aC₁₋₅₀-hydrocarbyl group since this restricts any cross-linking duringthe preparation of the dispersant. The hydrocarbyl group may beoptionally branched alkyl, cycloalkyl, aryl or aralkyl.

The cycloalkyl group is preferably C₃₋₆-cycloalkyl such as cyclopropyland especially cyclohexyl.

The aryl group is preferably C₆₋₁₀-aryl such as naphthyl and especiallyphenyl which may be substituted by halogen, C₁₋₂₀-alkyl or C₁₋₂₀-alkoxy.

The aralkyl group is preferably 2-phenylethyl and especially benzylwhere the phenyl ring is optionally substituted by halogen, C₁₋₂₀-alkylor C₁₋₂₀-alkoxy.

The length of the alkyl terminating group of the polyester, polyether,polyacrylate, or polyolefin chain depends to a large extent on thenature of the organic medium. Thus, for example, when the organic mediumis a polar organic liquid, the hydrocarbyl group is preferablyC₁₋₁₂-alkyl which may be linear or branched. The hydrocarbyl groupincludes ethyl, propyl, isopropyl or mixtures thereof. When thepolyurethane dispersant contains polyether side chains it is preferredthat the terminating alkyl group is C₁₋₄ alkyl, for instance methyl,because of their ready commercial availability. When the organic mediumis a non-polar organic liquid it is preferred that the terminating alkylgroup contains greater than 8 carbon atoms. It is also preferred thatthe alkyl group is branched since this aids solubility in the non-polarorganic liquid.

The polyether chain is preferably poly(C₂₋₄-alkylene oxide) whichcontains less than 60%, more preferably less than 40%, and especiallyless than 20% by weight ethylene oxide relative to the total weight ofthe poly(C₂₋₄-alkylene oxide) chain.

The alkylene moiety of the (C₂₋₄-alkylene oxide) group may be linear orpreferably branched and may be obtained by (co)polymerisation ofalkylene oxides such as ethylene oxide, propylene oxide and butyleneoxide or from tetrahydrofuran. Copolymers may be random or blockcopolymers.

Preferably, the polyether chain is obtainable from propylene oxide. Itis also preferred that the polyether chain of the dispersant isobtainable from a poly(C₂₋₄-alkylene oxide) mono-C₁₋₁₀-alkyl ether andespecially a methyl or butyl ether.

The polyester chain is preferably obtainable or obtained from a hydroxycarboxylic acid containing from 1 to 26 carbon atoms or a lactonethereof. The choice of hydroxy carboxylic acid is largely influenced bythe nature of the organic medium itself. Where the organic medium is apolar organic liquid, the hydroxy carboxylic acid preferably contains upto 8 carbon atoms and where the organic medium is a non-polar organicliquid the hydroxy carboxylic acid preferably contains more than 8carbon atoms. It is particularly preferred that the polyester chain isobtainable from two or more different hydroxy carboxylic acids orlactones thereof since this aids solubility in the organic medium. Thehydroxy carboxylic acid may be saturated or unsaturated, linear orbranched.

Examples of suitable hydroxy carboxylic acids are glycolic acid, lacticacid, 5-hydroxy valeric acid, 6-hydroxy caproic acid, ricinoleic acid,12-hydroxy stearic acid, 12-hydroxydodecanoic acid, 5-hydroxydodecanoicacid, 5-hydroxydecanoic acid and 4-hydroxydecanoic acid.

Examples of suitable lactones are β-propiolactone and optionallyC₁₋₆-alkyl substituted δ-valerolactone and ε-caprolactone such asβ-methyl-δ-valerolactone, δ-valerolactone, ε-caprolactone, 2-methyl,3-methyl, 4-methyl, 5-tert butyl, 7-methyl-, 4,4,6-trimethyl- and4,6,6-trimethyl-ε-caprolactone, including mixtures thereof.

Polyester chains derivable from δ-valerolactone and ε-caprolactone areespecially preferred.

The polyacrylate chains are preferably obtainable or obtained by(co)polymerising C₁₋₆-(alk)acrylate esters and especially (meth)acrylateesters (e.g. polymers from acrylic acid (optionally C₁₋₆ alkylsubstituted) or esters from C₁₋₁₈ (more preferably C₁₋₈) alcohols andacrylic or C₁₋₆ alkyl substituted acrylic acid).

As disclosed hereinbefore, the polyurethane dispersants may containmixtures of polyester, polyether and polyacrylate lateral side chains.

By way of an obvious variant, the polyester, polyether and polyacrylatelateral side chains may themselves be mixtures of such chains. Thus, forexample, the polyester and polyacrylate side chains may contain apolyether moiety and so on.

The number-average molecular weight of the lateral polyester, polyether,polyacrylate, or polyolefin side chains in the polyurethane dispersantis preferably not greater than 10,000, more preferably not greater than4,000 and especially not greater than 2,500. It is also preferred thatthe number-average molecular weight of the lateral polyester, polyetherand polyacrylate side chains is not less than 300, more preferably notless than 600 and especially not less than 800.

As disclosed hereinbefore, the backbone of the polyurethane isessentially linear. Therefore, the isocyanates from which the dispersantis obtainable preferably have a functionality of from 2.0 to 2.5, morepreferably from 2.0 to 2.1 and especially approximately 2.0.

The lateral side chain polyester, polyether, polyacrylate or polyolefinchains are connected to polyurethane backbone by oxygen and/or nitrogenatoms which are the residue of terminating hydroxy and amino (primaryand secondary) groups of the polyester, polyether, polyacrylic(especially polyacrylate) or polyolefin.

When the lateral side chain is a polyether it is preferably the residueof a polyether which contains either two hydroxyl groups or one hydroxyland one secondary amino group which react with isocyanates at one end ofthe polyether chain. The hydroxyl and amino groups are preferablyseparated by up to 6 carbon atoms. When the polyether contains twohydroxyl groups which react with isocyanates they are preferablyseparated by up to 17 atoms, especially 16 carbon atoms and one nitrogenatom. It is also preferred that the two hydroxyl groups are separated bynot less than 5 atoms, especially 4 carbon atoms and one nitrogen atom.It is also possible to prepare the dispersant from a polyether whichcontains two amino groups (i.e. primary and/or secondary amino groups)which react with isocyanates but this is less preferred.

When the lateral side chain is a polyester, it is preferably the residueof the polyester which contains two hydroxyl groups at one end of thepolyester chain which react with isocyanates. The hydroxyl groups arealso preferably separated by up to 17 atoms, especially 16 carbon atomsand one nitrogen atom. It is especially preferred that the two hydroxylgroups are separated by not less than 5 atoms.

When the lateral side chain is a polyacrylate it is preferably theresidue of a polyacrylate which contains two hydroxy groups at one endof the polyacrylate chain which react with isocyanates. The two hydroxylgroups are preferably separated by up to 4 carbon atoms, for example 2carbon atoms. In one embodiment the polyacrylate is present and inanother embodiment the polyacrylate is absent.

When the lateral side chain is a polyolefin it is preferably the residueof a polyolefin which contains either two hydroxyl groups or onehydroxyl and one secondary amino group which react with isocyanates atone end of the polyolefin chain. The hydroxyl and amino groups arepreferably separated by up to 6 carbon atoms. When the polyolefincontains two hydroxyl groups which react with isocyanates they arepreferably separated by up to 17 atoms, especially 16 carbon atoms andone nitrogen atom. It is also preferred that the two hydroxyl groups areseparated by not less than 5 atoms, especially 4 carbon atoms and onenitrogen atom. It is also possible to prepare the dispersant from apolyolefin which contains two amino groups (i.e. primary and/orsecondary amino groups) which react with isocyanates but this is lesspreferred.

The dispersant may also optionally contain an acid and/or amino group,including salts thereof, since such groups have been found to improvethe dispersibility of some particulate solids. The amount of acid and/oramino groups in the polyurethane dispersant is preferably from 10 to180, more preferably from 20 to 110 and especially from 20 to 60milliequivalents for each 100 g polyurethane dispersant. Acid groups arepreferred, especially carboxylic acid groups.

When the acid group is in the form of a salt, it may be the salt of analkali metal such as sodium, potassium or lithium, a salt of an aminesuch as C₁₋₈-alkylamine or C₁₋₈-alkanolamine or a salt of a quaternaryammonium cation such as a C₁₋₈-alkyl quaternary ammonium cation orbenzalkonium cation. The amino group may be quaternised by reaction witha dialkyl sulphate, such as dimethyl sulphate or benzyl chloride.Preferably the acid group, when present, is in the form of the freeacid.

When the amino group is in the form of a salt, it may be the salt of aninorganic or organic acid. Examples of such acids are hydrochloric acidand acetic acids. Preferably, the amino group, when present, is in anon-ionised form.

The polyurethane dispersant may also contain the residue of formativecompounds having a number average molecular weight of from 32 to 3,000together with two groups which react with isocyanates.

The polyurethane dispersant may also have terminal polyester, polyether,polyacrylate or polyolefin chains. Such chains are similar to thosedescribed hereinbefore for the lateral chains but are obtainable fromcompounds having only the one group which reacts with isocyanates.

The total weight percentage of the solvent-soluble lateral and terminalchains in the polyurethane dispersant is preferably not less than 20%,more preferably not less than 30% and especially not less than 40%. Itis also preferred that the total weight percentage of solvent-solublelateral and terminal chains in the polyurethane dispersant is notgreater than 90%, more preferably not greater than 80%, for instance 45%to 80% or 60% to 78%. In one embodiment the total weight percentage ofsolvent-soluble lateral and terminal chains in the polyurethanedispersant is not greater than 70%, for instance 55% to 65%.

The weight percentage of solvent-soluble lateral chains in thepolyurethane dispersant is preferably not less than 5%, more preferablynot less than 15% and especially not less than 25% or not less than 35%.

The particulate solid present in the composition may be any inorganic ororganic solid material which is substantially insoluble in the organicmedium at the temperature concerned and which it is desired to stabilisein a finely divided form therein.

Examples of suitable solids are pigments for solvent inks; pigments,extenders and fillers for paints and plastics materials; dyes,especially disperse dyes; optical brightening agents and textileauxiliaries for solvent dyebaths, inks and other solvent applicationsystems; solids for oil-based and invert-emulsion drilling muds; dirtand solid particles in dry cleaning fluids; particulate ceramicmaterials; magnetic materials and magnetic recording media, fireretardants such as those used in plastics materials and biocides,agrochemicals and pharmaceuticals which are applied as dispersions inorganic media.

A preferred particulate solid is a pigment from any of the recognisedclasses of pigments described, for example, in the Third Edition of theColour Index (1971) and subsequent revisions of, and supplementsthereto, under the chapter headed “Pigments”. Examples of inorganicpigments are titanium dioxide, zinc oxide, Prussian blue, cadmiumsulphide, iron oxides, vermilion, ultramarine and the chrome pigments,including chromates, molybdates and mixed chromates and sulphates oflead, zinc, barium, calcium and mixtures and modifications thereof whichare commercially available as greenish-yellow to red pigments under thenames primrose, lemon, middle, orange, scarlet and red chromes. Examplesof organic pigments are those from the azo, disazo, condensed azo,thioindigo, indanthrone, isoindanthrone, anthanthrone, anthraquinone,isodibenzanthrone, triphendioxazine, quinacridone and phthalocyanineseries, especially copper phthalocyanine and its nuclear halogenatedderivatives, and also lakes of acid, basic and mordant dyes. Carbonblack, although strictly inorganic, behaves more like an organic pigmentin its dispersing properties. Preferred organic pigments arephthalocyanines, especially copper phthalocyanines, monoazos, disazos,indanthrones, anthranthrones, quinacridones and carbon blacks.

Other preferred particulate solids are: extenders and fillers such astalc, kaolin, silica, barytes and chalk; particulate ceramic materialssuch as alumina, silica, zirconia, titania, silicon nitride, boronnitride, silicon carbide, boron carbide, mixed silicon-aluminiumnitrides and metal titanates; particulate magnetic materials such as themagnetic oxides of transition metals, especially iron and chromium, e.g.gamma-Fe₂O₃, Fe₃O₄, and cobalt-doped iron oxides, calcium oxide,ferrites, especially barium ferrites; and metal particles, especiallymetallic iron, nickel, cobalt and alloys thereof; agrochemicals such asthe fungicides flutriafen, carbendazim, chlorothalonil and mancozeb andfire retardants such as aluminium trihydrate and magnesium hydroxide.

The organic medium present in the composition is preferably a polarorganic medium or a substantially non-polar aromatic hydrocarbon orhalogenated hydrocarbon. By the term “polar” in relation to the organicmedium is meant an organic liquid or resin capable of forming moderateto strong bonds as described in the article entitled “A ThreeDimensional Approach to Solubility” by Crowley et al in Journal of PaintTechnology, Vol. 38, 1966, at page 269. Such organic media generallyhave a hydrogen bonding number of 5 or more as defined in the abovementioned article.

Examples of suitable polar organic liquids are amines, ethers,especially lower alkyl ethers, organic acids, esters, ketones, glycols,alcohols and amides. Numerous specific examples of such moderatelystrongly hydrogen bonding liquids are given in the book entitled“Compatibility and Solubility” by Ibert Mellan (published in 1968 byNoyes Development Corporation) in Table 2.14 on pages 39-40 and theseliquids all fall within the scope of the term polar organic liquid asused herein.

Preferred polar organic liquids are dialkyl ketones, alkyl esters ofalkane carboxylic acids and alkanols, especially such liquids containingup to, and including, a total of 6 carbon atoms. As examples of thepreferred and especially preferred liquids there may be mentioneddialkyl and cycloalkyl ketones, such as acetone, methyl ethyl ketone,diethyl ketone, di-isopropyl ketone, methyl isobutyl ketone, di-isobutylketone, methyl isoamyl ketone, methyl n-amyl ketone and cyclohexanone;alkyl esters such as methyl acetate, ethyl acetate, isopropyl acetate,butyl acetate, ethyl formate, methyl propionate, methoxy propylacetateand ethyl butyrate; glycols and glycol esters and ethers, such asethylene glycol, 2-ethoxyethanol, 3-methoxypropylpropanol,3-ethoxypropylpropanol, 2-butoxyethyl acetate, 3-methoxypropyl acetate,3-ethoxypropyl acetate and 2-ethoxyethyl acetate; alkanols such asmethanol, ethanol, n-propanol, isopropanol, n-butanol and isobutanol anddialkyl and cyclic ethers such as diethyl ether and tetrahydrofuran.

The substantially non-polar, organic liquids which may be used, eitheralone or in admixture with the aforementioned polar solvents, arearomatic hydrocarbons, such as toluene and xylene, aliphatichydrocarbons such as hexane, heptane, octane, decane, petroleumdistillates such as white spirit, mineral oils, vegetable oils andhalogenated aliphatic and aromatic hydrocarbons, such astrichloro-ethylene, perchloroethylene and chlorobenzene.

Examples of suitable polar resins, as the medium for the dispersion formof the present invention, are film-forming resins such as are suitablefor the preparation of inks, paints and chips for use in variousapplications such as paints and inks. Examples of such resins includepolyamides, such as Versamid™ and Wolfamid™, and cellulose ethers, suchas ethyl cellulose and ethyl hydroxyethyl cellulose. Examples of paintresins include short oil alkyd/melamine-formaldehyde,polyester/melamine-formaldehyde, thermosettingacrylic/melamine-formaldehyde, long oil alkyd and multi-media resinssuch as acrylic and urea/aldehyde.

The resin may also be an unsaturated polyester resin including theso-called sheet moulding compounds and bulk moulding compounds which maybe formulated with reinforcing fibres and fillers. Such mouldingcompounds are described in DE 3,643,007 and the monograph by P F Bruinsentitled “Unsaturated Polyester Technology”, Gordon and Breach Sciencepublishers, 1976, pages 211 to 238.

If desired, the dispersions may contain other ingredients, for exampleresins (where these do not already constitute the organic medium)binders, fluidising agents (such as those described in GB-A-1508576 andGB-A-2108143), anti-sedimentation agents, plasticizers, levelling agentsand preservatives.

The composition typically contains from 5 to 95% by weight of theparticulate solid, the precise quantity depending on the nature of thesolid and the relative densities of the solid and the organic medium.For example, a composition in which the solid is an organic material,such as an organic pigment, preferably contains from 15 to 60% by weightof the solid whereas a composition in which the solid is an inorganicmaterial, such as an inorganic pigment, filler or extender, preferablycontains from 40 to 90% by weight of the solid based on the total weightof composition.

The composition is preferably prepared by milling the particulate solidin the organic medium at a temperature which is not greater than 40° C.and especially not greater than 30° C. However, when the solid is acrude phthalocyanine pigment such as copper phthalocyanine, it issometimes preferable to carry out the milling in an organic liquid at atemperature between 50 and 150° C. since greener and brighter shades maybe obtained. This is particularly the case where the organic liquid is ahigh boiling aliphatic and/or aromatic distillate.

The composition may be obtained by any of the conventional methods knownfor preparing dispersions. Thus, the solid, the organic medium and thedispersant may be mixed in any order, the mixture then being subjectedto a mechanical treatment to reduce the particles of the solid to anappropriate size, for example by ball milling, bead milling, gravelmilling or plastic milling until the dispersion is formed.Alternatively, the solid may be treated to reduce its particle sizeindependently or in admixture with either the organic medium or thedispersant, the other ingredient or ingredients then being added and themixture being agitated to provide the dispersion.

If the composition is required in dry form, the liquid medium ispreferably volatile so that it may be readily removed from theparticulate solid by a simple separation means such as evaporation. Itis preferred, however, that the composition comprises the liquid medium.

If the dry composition consists essentially of the dispersant and theparticulate solid, it preferably contains at least 0.2%, more preferablyat least 0.5% and especially at least 1.0% dispersant based on weight ofthe particulate solid. Preferably the dry composition contains notgreater than 100%, preferably not greater than 50%, more preferably notgreater than 20% and especially not greater than 10% by weightdispersant based on the weight of the particulate solid.

As described hereinbefore, the compositions are particularly suitablefor preparing mill-bases where the particulate solid is milled in aliquid medium in the presence of both a particulate solid and afilm-forming resin binder.

Thus, according to a still further aspect of the invention there isprovided a mill-base comprising a particulate solid, dispersant and afilm-forming resin.

Typically, the mill-base contains from 20 to 70% by weight particulatesolid based on the total weight of the mill-base. Preferably; theparticulate solid is not less than 30 and especially not less than 50%by weight of the mill-base.

The amount of resin in the mill-base can vary over wide limits but ispreferably not less than 10%, and especially not less than 20% by weightof the continuous/liquid phase of the mill-base. Preferably, the amountof resin is not greater than 50% and especially not greater than 40% byweight of the continuous/liquid phase of the mill-base.

The amount of dispersant in the mill-base is dependent on the amount ofparticulate solid but is preferably from 0.5 to 5% by weight of themill-base.

The polyurethane dispersants may be prepared by any method known to theart and are obtainable or obtained by reacting together:

a) one or more polyisocyanates having an average functionality of from2.0 to 2.5;

b) one or more compounds having at least one polyester, polyether,polyacrylate or polyolefin chain and at least two groups which reactwith isocyanates which are located at one end of the compound such thatthe polyester, polyether or polyacrylate chain(s) is laterally disposedin relation to the polyurethane polymer backbone;

c) optionally, one or more compounds having an acid or amino group,including salts thereof, and at least two groups which react withisocyanates;

d) optionally, one or more formative compounds having a number averagemolecular weight of from 32 to 3,000 which have at least two groupswhich react with isocyanates;

e) optionally, one or more compounds which act as chain terminatorswhich contain one group which reacts with isocyanates;

f) optionally, one or more compounds which act as chain terminatorswhich contain a single isocyanate group.

As noted hereinbefore the polyurethane dispersants have an essentiallylinear backbone and consequently it is much preferred that components(b), (c) and (d) contain only two groups which react with isocyanates.It is also preferred that component (a) has a functionality of from 2.1to 2.0 and especially about 2 since this also limits any cross-linkingbetween chains of the polyurethane dispersants.

Preferably, component (a) is a diisocyanate or mixtures of diisocyanatessuch as toluene diisocyanate (TDI), isophorone diisocyanate (IPDI),hexanediisocyanate (HDI), α,α-tetramethylxylene diisocyanate (TMXDI),diphenylmethane-4,4′-diisocyanate (4,4′-MDI),diphenylmethane-2,4′-diisocyanate (2,4′-MDI) anddicyclohexylmethane-4,4′-diisocyanate (HMDI). Preferably, component (a)is either TDI or IPDI or MDI.

The compound having a polyether chain which is component (b) ispreferably poly(C₂₋₃-alkylene oxide) which contains less than 60%poly(ethylene oxide) and also preferably contains two groups which reactwith isocyanates. Preferably, the amount of ethylene oxide is less than40% and especially less than 20% by weight of the poly(C₂₋₃-alkyleneoxide) chain. There are a number of ways of incorporating a polyetherlateral chain into an organic compound which contains these groups whichreact with isocyanates.

Thus, in the case where the two groups which react with isocyanates areboth hydroxyl, a poly(C₂₋₄-alkylene oxide) chain may be convenientlyattached by isocyanates having a functionality of two or more. Compoundsof this type are described in U.S. Pat. No. 4,794,147, which involvessequentially reacting a mono-functional polyether with a polyisocyanateto produce a partially capped isocyanate intermediate and reacting theintermediate with a compound having at least one active amino hydrogenand at least two active hydroxyl groups.

One preferred class of compound of this type may be presented by theformula 1.

wherein

R is C₁₋₂₀-hydrocarbyl group;

R¹ is hydrogen, methyl or ethyl of which less than 60% is hydrogen;

R² and R³ are each, independently, C₁₋₈-hydroxyalkyl;

Z is C₂₋₄-alkylene;

X is —O— or —NH—;

Y is the residue of a polyisocyanate;

m is from 5 to 150;

p is from 1 to 4; and

q is 1 or 2.

R may be alkyl, aralkyl, cycloalkyl or aryl.

When R is aralkyl, it is preferably benzyl or 2-phenylethyl.

When R is cycloalkyl it is preferably C₃₋₈-cycloalkyl such ascyclohexyl.

When R is aryl it is preferably naphthyl or phenyl.

When R is alkyl, it may be linear or branched and preferably containsnot greater than 12, more preferably not greater than 8 and especiallynot greater than 4 carbon atoms. It is especially preferred that R ismethyl or butyl.

The C₂₋₄-alkylene radical represented by Z may be ethylene,trimethylene, 1,2-propylene or butylene.

Preferably m is not less than 10. It is also preferred that m is notgreater than 100 and especially not greater than 80.

When q is 2 it is possible to link two different polyurethane polymerchains but it is much preferred that q is 1.

When the polyisocyanate has a functionality which is greater than 2, thecompound which is component (b) may carry more than one poly(alkyleneoxide) chain. However, it is much preferred that p is 1, q is 1 and thatY is the residue of a diisocyanate.

When R¹ is a mixture of hydrogen and methyl and Z is 1,2-propylene and Xis —NH— the compound of formula 1 is a derivative of polyalkylene glycolamine such as a Jeffamine™ M polyether available from HuntsmanCorporation.

Preferably, R² and R³ are both 2-hydroxyethyl.

It is also preferred that X is O.

Compounds of formula 1 are typically prepared by reacting amono-functional polyether with a polyisocyanate in an inert solvent suchas toluene at a temperature of from 50 to 100° C. until the desiredisocyanate value is reached optionally in the presence of an acidcatalyst. In one embodiment the acid catalyst is present and in anotherembodiment the acid catalyst is absent. The temperature is then normallyreduced to between 40 and 60° C. when the requisite secondary amine suchas diethanolamine is added.

Useful compounds of formula 1 have been used as component (b) byreacting a poly(propylene glycol) mono methyl ether, a poly(propyleneglycol) mono butyl ether or a Jeffamine™ M series polyether having anumber average molecular weight of from 250 to 5,000 with a diisocyanatesuch as TDI followed by diethanolamine.

A second preferred type of compound which can be used as component (b)is of formula 2.

wherein

R, R¹, Z and m are as defined hereinbefore;

R⁴ is an isocyanate reactive organic radical (group);

R⁵ is hydrogen or an isocyanate-reactive organic radical; and

n is 0 or 1.

Examples of compounds of formula 2 are disclosed in EP 317258.

The organic radical represented by R⁴, and R⁵ is an organic radicalcontaining an isocyanate-reactive group, such as —OH, —SH, —COOH, —PO₃H₂and —NHR⁶ in which R⁶ is hydrogen or optionally substituted alkyl. Asspecific examples of isocyanate-reactive radicals, there may bementioned hydroxyalkyl, hydroxy alkoxy alkyl, hydroxy(poly alkylene oxy)alkyl and hydroxy alkoxy carbonyl alkyl.

A preferred type of compound of formula 2 is where n is zero, Z is1,2-propylene, R⁴ is —CH₂CH₂C(O)—O-(L)_(q)-H. Wherein L is a hydrocarbylgroup or alkoxy group, preferably L is a C₂ to C₃ hydrocarbyl group oralkoxy group; and q is 1 to 20, preferably 1 to 6 and most preferably 1.R⁵ is hydrogen. Compounds of this type are obtainable or obtained by theMichael addition reaction of a poly(alkylene oxide) monoalkyl ethermonoamine and a hydroxy functional acrylate such as 2-hydroxyethylacrylate or hydroxypropyl acrylate. A suitable source of poly(alkyleneoxide) monoalkyl ether monoamine is the Jeffamine™ M series ofpolyethers available from Huntsman Corporation. The reaction between thepoly(alkylene oxide) mono alkylether monoamine and 2-hydroxy functionalacrylate is typically carried out in the presence of air and at atemperature of 50 to 100° C., optionally in the presence of apolymerisation inhibitor such as hydroquinone or butylated hydroxytoluene.

Another preferred type of compound of formula 2 is where n is zero, Z is1,2-propylene and R⁴ and R⁵ are both 2-hydroxyethyl. Compounds of thistype may be prepared by reacting a poly(alkylene oxide) mono alkyl ethermono amine with ethylene oxide under acidic conditions.

Yet another preferred type of compound of formula 2 is where n is zero,Z is 1,2-propylene and R⁴ is —CH₂CH₂C(O)—O-(L)_(q)-H and R⁵ is hydrogen.Wherein L is a hydrocarbyl group or alkoxy group, preferably L is a C₂to C₃ hydrocarbyl group or alkoxy group; and q is 1 to 20, preferably 1to 6 and most preferably 1. R⁵ is hydrogen. Compounds of this type maybe prepared by reacting a poly(alkylene oxide) mono alkyl ether monoamine with about one stoichiometric equivalent of ethylene oxide underacidic conditions.

Poly(alkylene oxide) monoalkyl ether monoamines may also be obtainedfrom reaction of a poly(alkylene oxide) monoalkyl ether withacrylonitrile and hydrogen reduction according to the following generalscheme where R and R¹ are as previously described.

A further preferred type of compound of formula 2 where n is zero, Z is1,3-propylene and R⁴ is 2-hydroxyethyl and R⁵ is hydrogen may beobtained from reaction between poly(alkylene oxide) monoalkyl ethermonoamines of formula 2A and a hydroxy functional acrylate such as2-hydroxyethyl acrylate or hydroxypropyl acrylate.

A third preferred type of compound which may be used as component (b) isof formula 3:

wherein R, R¹ and m are as defined hereinbefore and W is C₂₋₆-alkyleneand especially ethylene. Compounds of this type are obtainable orobtained by the Michael addition reaction of a hydroxy amine and apoly(alkylene oxide) acrylate.

A fourth preferred type of compound which may be used as component (b)is of formula 4.

whereinR, R¹, Z, m and n are as defined hereinbefore;R⁷ represents hydrogen, halogen or C₁₋₄ alkyl;Q is a divalent electron withdrawing group; andT is a divalent hydrocarbon radical which may carry substituents orcontain hetero atoms.

Examples of electron withdrawing groups which may be represented by Qinclude —CO—, —COO—, —SO—, —SO₂—, —SO₂O— and —CONR⁸— in which R⁸ ishydrogen or alkyl.

Hydrocarbon radicals which may be represented by T include alkylene,arylene and mixtures thereof, said radicals optionally carryingsubstituents or containing hetero-atoms. Examples of suitable radicalsrepresented by T are alkylene radicals containing from 1 to 12 carbonatoms, oxyalkylene and

polyoxyalkylene radicals of the formula —(CH₂CHR¹O)_(x) wherein R¹ is asdefined hereinbefore and x is from 1 to 10, phenylene and diphenyleneradicals and other arylene radicals such aswherein Y is —O—,—S—,—CH₂—,—CO— or —SO₂—

The compounds of Formula 4 are obtainable or obtained by the Michaeladdition reaction of two moles of a poly(alkylene oxide) monoalkyl ethermonoamine with one mole of an unsaturated compound of the formula 5.

wherein Q, T and R⁷ are as defined hereinbefore.

Examples of unsaturated compounds of Formula 5 are especiallydiacrylates and dimethacrylates wherein T is a C₄₋₁₀-alkylene residue, apolyoxyalkylene residue or an oxyethylated Bisphenol A residue.

When component (b) is a polyester containing two groups which react withisocyanates the polyester chain may be made by polymerising one or morehydroxy carboxylic acids or lactones thereof in the presence of either ahydroxy or carboxy containing compound which acts as a polymerisationterminating moiety.

The polyester obtained using a hydroxy containing compound as chainterminating compound is preferably of formula 6.R⁹O(OC-A-O)_(m)H  6wherein

m is as defined hereinbefore;

R⁹ is C₁₋₅₀-hydrocarbyl group; and

A is C₁₋₂₆-alkylene and/or C₂₋₂₆-alkenylene.

The polyester obtained using a carboxylic containing compound as chainterminating compound is preferably of formula 7.R⁹CO(O-A-CO)_(m)OH  7wherein

R⁹, A and m are defined hereinbefore.

The polyester of Formulae 6 and/or 7 are typically made by reacting oneor more hydroxy carboxylic acids together with either a hydroxycontaining compound or carboxy containing compound at 50 to 250° C. inan inert atmosphere and in the presence of an esterification catalyst:Typical process conditions are described in WO 01/80987.

Compounds of Formula 6 may be reacted with a polyisocyanate and asecondary amine under similar conditions described for the preparationof compounds of Formula 1 to form polyester analogues.

Compounds of Formula 7 may be converted to a mono hydroxy compound byreacting with a diol such as ethylene glycol or propylene glycol and theresulting mono hydroxy derivative treated in similar manner to thecompound of Formula 6 in preparing polyester analogues to the polyetherof Formula 1.

A polyester which contains 2 functional groups which are reactivetowards an isocyanate at one end of the polyester may be prepared by theMichael addition of an aminoalcohol with a polyester acrylate such as apolycaprolactone acrylate with ethanolamine.

When component (b) is a compound which contains a poly(alk)acrylatechain it is preferably a poly(meth)acrylate containing either twohydroxyl groups at one end of the acrylate chain or one hydroxyl and oneimino group at one end of the acrylate chain. The two hydroxyl groups orthe one hydroxyl and one imino group are preferably separated by 1 to 6carbon atoms. Polyacrylates of this type are obtainable or obtained byreacting a diol with an acrylate by, for example, Atom Transfer RadicalPolymerisation as illustrated by the following reaction scheme.Reactions of this type are disclosed in Macromolecules 1995, 28, 1721and 1997, 30, 2190 and in J. Am. Chem. Soc. 1995, 117, 5614.

wherein R¹⁰ is C₁₋₂₀-hydrocarbyl group and m is as defined hereinbefore.

Alternatively, a dihydroxy functional poly(alk)acrylate may be preparedby the free radical polymerisation of a (meth)acrylate monomer(s) in thepresence of a dihydroxy functional chain transfer agent such asthioglycerol according to the following reaction scheme.

The reaction is preferably carried out in the presence of an initiatorsuch as azo bis-(isobutyronitrile) (AIBN).

wherein R¹⁰ and m are as defined hereinbefore.

Monohydroxy functional polymer chains (polyether, polyester orpoly(alk)acrylate) may be converted to polymer chains containing both ahydroxyl and imino group at one end by first reaction with an isocyanatefunctional acrylate followed by a Michael addition of an alkanolamine tothe resulting adduct.

The following scheme illustrates such a synthetic conversion startingwith a monohydroxy functional polyester.

wherein R¹⁰ and m are as defined hereinbefore.

When component (b) is a compound which contains a polyolefin chain it ispreferably a polyolefin containing either two hydroxyl groups at one endof the polyolefin chain or one hydroxyl and one imino group at one endof the polyolefin chain. It is preferred that the polyolefin chain ispolyisobutylene. Polyisobutylene chains which contain 2 or moreisocyanate reactive groups at one end of the chain may be prepared frompolyisobutenyl succinic anhydride (PIBSA). Reaction of PIBSA with analkyl diamine yields a polyisobutylene with a primary amine on one

end. This is illustrated for one type of PIBSA:

The primary amine ended polyisobutylene chain may be converted to yielda product with two isocyanate reactive groups by Michael addition of ahydroxy functional acrylate or addition of ethylene oxide in ananalogous way to that described above for poly(alkylene oxide) monoalkylether monoamines.

As disclosed hereinbefore component (c) is a compound containing an acidor amine group and at least two groups which react with isocyanates.Preferably the compound contains only two groups which react withisocyanates since this restricts cross-linking between adjacent chainsof the dispersant. Acid groups are preferred. The acid group may bephosphonic, sulphonic or preferably carboxylic, including mixturesthereof. Preferably, the groups of component (c) which react withisocyanates are both hydroxy groups. A preferred diol which is component(a) is a compound of formula 8.

wherein at least two of the groups R¹¹, R¹² and R¹³ are C₁₋₆-hydroxyalkyl and the remainder is C₁₋₆-hydrocarbyl group, which may be linearor branched alkyl, aryl, aralkyl or cycloalkyl, M is hydrogen or analkaline metal cation, or quaternary ammonium cation. Preferred examplesof carboxylic acid components are dimethylolpropionic acid (DMPA) anddimethylolbutyric acid (DMBA).

The acid containing compound which is component (c) may contain otheracid groups in addition to or instead of a carboxylic group(s), such asphosphonic or sulphonic acid groups. An example of one such compound is1,3-benzene dicarboxylic acid-5-sulpho-1,3-bis(2-hydroxyethyl) ester(EGSSIPA).

When component (c) carries a basic group in addition to the two groupswhich react with isocyanates it is essential that the basic group doesnot react with isocyanates. Basic groups of this type are aliphatictertiary amines, hindered aromatic amines and nitrogen heterocycliccompounds which may be alicyclic or aromatic. Examples of hinderedaromatic amines are phenylamines having a steric hindering group, in the2 and/or 6-position. Specific examples of component (c) having a basicgroup are N-methyl diethanolamine (NMDA), N-phenyldiethanolanine (NPDA)and N,N-bis(2-hydroxyethyl) isonicotinamide (HEINA).

The formative compounds which are component (d) of the polyurethane arepreferably difunctional in respect of reactivity with isocyanatesalthough a small amount of higher functionality may be used where asmall amount of branching of the polyurethane polymer backbone isdesired. However, it is preferred that component (d) is difunctional.Preferred reactive groups are amino and hydroxy and it is much preferredthat component (d) is a diamine or especially a diol. Component (d), ifpresent, is used primarily as a chain extender to alter the solubilityof the polyurethane polymer.

Examples of suitable diamines are ethylene diamine, 1,4-butane diamineand 1,6-hexane diamine.

Examples of suitable diols are 1,6-hexanediol, 1,4-cyclohexanedimethanol(CHDM), 1,2-dodecanediol, 2-phenyl-1,2-propanediol, 1,4-benzenedimethanol, 1,4-butanediol and neopentyl glycol. The diol may also be apolyether such as a poly(C₂₋₄-alkylene glycol), a polyester orpolyacrylic diol. The polyalkylene glycol may be a random or block(co)polymer containing repeat ethyleneoxy, propyleneoxy or butyleneoxygroups, including mixtures thereof.

As noted hereinbefore, it is preferred that the polyurethane polymerbackbone is essentially linear in character. However, some small amountof branching may be tolerated and this branching may conveniently beintroduced by means of a higher functional polyol such as trimethylolpropane, trimethylolethane or pentaerythritol.

As disclosed hereinbefore the chain terminating compound which iscomponent

(e) is mono-functional with respect to the isocyanate. Themonofunctional group is preferably an amino or hydroxy group. Preferredterminating groups are poly(C₂₋₄-alkylene) mono alkyl ethers and monoalkyl ether amines similar to those used in the preparation of thelateral side chain compounds which are component (b) of thepolyurethane.

An example of a monoisocyanate which acts as a chain terminatingcompound (component f) is phenyl isocyanate.

It is much preferred that the amount of component (f) is zero.

Typical amounts of the aforementioned compounds from which thepolyurethane polymers are obtainable are 15-50% component (a), 10-80%component (b), 0-24% component (c), 0-25% component (d), 0-50% component(e) and 0-20% component (f), all based on the total weight of thepolyurethane polymer.

When component (e) is a monofunctional polyether, polyester,poly(alk)acrylate or polyolefin the total amount of component (b) withcomponent (e) is preferably not less than 35% and where component (e) isother than a monofunctional polyether, polyester or poly(alk)acrylatethe amount of component (h) is preferably not less than 35%.

The polyurethane polymers according to the invention may be prepared byany method known to the art. Typically, the polyurethane polymer isobtainable or obtained by reacting one or more isocyanates having afunctionality of from 2.0 to 2.5 (component (a)) with one or morecompounds selected from polyethers having a poly(C₂₋₄-alkylene oxide)chain, polyester, polyacrylic, or polyolefin, each characterized byhaving at least two groups which react with isocyanates which arelocated at one end (component (b)) under substantially anhydrousconditions and in an inert atmosphere which is typically a temperaturebetween 0 and 130° C., optionally in the presence of an inert solventand optionally in the presence of a catalyst. Optionally, the reactionmay also be carried out in the presence of one or more compounds havingat least one acid or amine group (component (c)) and one or moreformative compounds acting as chain extenders (component (d)) andoptionally one or more compounds which act as chain terminatingcompounds which are components (e) and (f).

The inert atmosphere may be provided by any of the inert gases of thePeriodic Table but is preferably nitrogen.

The preparation of the polyurethane polymer/prepolymer may be carriedout in the presence of a catalyst. Particularly preferred catalysts aretin complexes of aliphatic acids such as dibutyl tin dilaurate (DBTDL)and tertiary amines.

The essential feature of the polyurethane polymer according to theinvention is that it comprises a predominantly linear polyurethanepolymer backbone containing the defined amount of lateral polymeric sidechains which may poly(alkylene oxide), polyester, poly(alk)acrylate orpolyolefin. There will thus be many variants which will be obvious tothe skilled addressee regarding the ratio of isocyanate groups toisocyanate reactive groups including the formulation of prepolymerswhich have residual isocyanate functionality. In one case, the ratio oftotal isocyanate groups provided by component (a) is less than the totalnumber of isocyanate reactive groups provided by component (b) andcomponents (c) (d) and (e) when present. Any terminal isocyanatereactive groups may be reacted.

Alternatively, the ratio of total number of isocyanate groups providedby component (a) and optionally component (f) is greater that the totalnumber of isocyanate reactive groups provided by component (b) andcomponents (c), (d) and (e) when present. The resultant polyurethane isthen a prepolymer containing residual isocyanate functionality. Thisprepolymer may then be reacted with other chain extenders such ascomponent (d) which conjoins different prepolymer chains and/or withchain terminating compounds which are component (e), optionally prior toor during dissolution in water or other polar solvent. In one embodimentprepolymer is reacted with chain extenders prior to dissolution in wateror other polar solvent. In one embodiment prepolymer is reacted withchain extenders during dissolution in water or other polar solvent. Inone embodiment prepolymer is reacted with chain extenders prior todissolution in the absence of water or other polar solvent. In oneembodiment the prepolymer may be reacted with chain extenders in theabsence of water.

The preparation of prepolymers can be useful since it is a means ofcontrolling viscosity during the preparation of the polyurethanepolymer, especially in circumstances where the reaction is carried outin the absence of any solvent.

When a prepolymer is formed which contains isocyanate functionality,chain extension may be carried out by water itself, or a polyol,amino-alcohol, a primary or secondary aliphatic, alicyclic, aromatic,araliphatic or heterocyclic polyamine especially a diamine, hydrazine ora substituted hydrazine.

Examples of suitable chain extenders include ethylenediamine, diethylenetriamine, triethylene tetramine, propylenediamine, butylenediamine,hexamethylenediamine, cyclohexylenediamine, piperazine, 2-methylpiperazine, phenylenediamine, tolylene diamine, xylylene diamine,tris(2-aminoethy)amine, 3,3′-dinitrobenzidine, 4,4′methylenebis(2-chloroaniline), 3,3′-dichloro-4,4′bi-phenyl diamine,2,6-diaminopyridine, 4,4′-diaminodiphenylmethane, methane diamine,m-xylene diamine, isophorone diamine, and adducts of diethylene triaminewith acrylate or its hydrolyzed products. Also materials such ashydrazine, azines such as acetone azine, substituted hydrazines such as,for example, dimethyl hydrazine, 1,6-hexamethylene-bis-hydrazine,carbodihydreazine, hydrazides of dicarboxylic acids and sulphonic acidsuch as adipic acid mono- or dihydrazide, xalic acid dihydrazide,isophthalic acid dihydrazide, tartaric acid dihydrazide, 1,3-phenylenedisulphonic acid dihydrazide, omega-aminocaproic acid dihydrazide,hydrazides made by reacting lactones with hydrazide such asgamma-hydroxylbutyric hydrazide, bis-semi-carbazide carbonic esters ofglycols such as any of the glycols mentioned above. Hexamethylenediamineis especially preferred.

The chain extension can be conducted at elevated, reduced or ambienttemperatures. Convenient temperatures are from about 5° C. to 95° C.

When employing a prepolymer in the preparation of the polyurethanepolymer, the amount of chain extender and chain terminating compound arechosen to control the molecular weight of the polyurethane polymer. Ahigh molecular weight will be favoured when the number ofisocyanate-reactive groups in the chain extender is approximatelyequivalent to the number of free isocyanate groups in the prepolymer. Alower molecular weight of the polyurethane polymer is favoured by usinga combination of chain extender and chain terminator in the reactionwith the polyurethane prepolymer.

An inert solvent may be added before, during or after formation of thepolyurethane polymer/prepolymer in order to control viscosity. Examplesof suitable solvents are acetone, methylethylketone, dimethylformamide,dimethylacetamide, diglyme, N-methylpyrrolidone, butylacetate,methoxypropyl acetate, ethylacetate, ethylene and propyleneglycoldiacetates, alkyl ethers of ethylene and propylene glycolacetates, toluene, xylene and sterically hindered alcohols such ast-butanol and diacetone alcohol. Preferred solvents are ethyl acetate,butyl acetate, methoxy propylacetate and N-methylpyrrolidone.

The number average molecular weight of the polyurethane polymer ispreferably not less than 2,000, more preferably not less than 3,000 andespecially not less than 4,000. It is also preferred that the numberaverage molecular weight of the polyurethane polymer is not greater than50,000, more preferably not greater than 30,000 and especially notgreater than 20,000.

As noted hereinbefore some of the polyurethane dispersants are novel.Hence, as a further aspect of the invention there is provided apolyurethane dispersant having an essentially linear backbone andlaterally attached solvent-solubilising polyether side chains ofpoly(C₂₋₄-alkylene oxide) which contains less than 60% by weightethylene oxide relative to the poly(C₂₋₄-alkylene oxide) chain. In onepreferred sub-group of such dispersants, the poly(C₂₋₄-alkylene oxide)chain is the residue of a polyether which contains one hydroxyl and oneimino (secondary amine) group at one end of the polyether chain whichreacts with isocyanates. In a second preferred sub-group of polyetherdispersants the poly(C₂₋₄-alkylene oxide) chain is the residue of apolyether which contains two hydroxyl groups at one end of the polyetherchain which react with isocyanates and which are separated by not lessthan 5 atoms.

In a further aspect of the invention there is provided a polyurethanedispersant having an essentially linear backbone and laterally attachedsolvent-solubilising polyether side chains of poly(C₂₋₄-alkylene oxide)which contains less than 60% by weight ethylene oxide relative to thepoly(C₂₋₄-alkylene oxide) chain and from 10 to 180 milliequivalents ofan ionic group (preferably carboxylic acid) for each 100 gm dispersant.

As a still further aspect of the invention there is provided apolyurethane dispersant having an essentially linear backbone andlaterally attached solvent-solubilising polyester side chains. In onepreferred sub-group of such polyester dispersants, the polyester sidechain is the residue of a polyester which contains two hydroxyl groupsat one end of the polyester chain which react with isocyanates and whichare preferably separated by from 5 to 17 atoms.

INDUSTRIAL APPLICATION

Dispersions and mill bases made from the composition of the inventionare particularly suitable for use in paints, including high solidspaints, inks, especially flexographic, gravure and screen inks, colourfilter layers for display screen equipment and non-aqueous ceramicprocesses.

The following examples provide an illustration of the invention. Theseexamples are non exhaustive and are not intended to limit the scope ofthe invention. Unless expressed to the contrary all references are toparts by weight.

EXAMPLES Preparation of Intermediates

Intermediate A—Dihydroxy Polyester (TDI, DEA, Cap, Val)

1-Dodecanol (54.77 parts, 0.294M), ε-caprolactone (318.48 parts, 2.79M)and δ-valerolactone (103 parts, 0.103M) were stirred together undernitrogen at 150° C. Zirconium butoxide catalyst (2.38 parts) was addedand the reactants were stirred under nitrogen for 20 hours at 180° C.After cooling to 20° C., the polyester was obtained as a waxy solid.This is Polyester 1.

Tolylene diisocyanate (16.37 parts) was added to a reaction vesselheated to 40° C. Polyester 1 (148.3 parts) dissolved in methoxypropylacetate (150 parts) was added over 40 minutes with stirring at 40-44° C.The reaction was continued with stirring at 50° C. for 75 minutes. Thereactants were then cooled to 35° C. and diethanolamine (9.89 parts) wasadded. The reaction was continued with stirring at 35° C. until noisocyanate remained. This is Intermediate A.

Intermediate B—Hydroxyamino PO Polyether

Jeffamine™ M2005 (200 parts), 2-hydroxyethyl acrylate (11.61 parts) and2,6-di-tert-butyl-4-methyl phenol (0.03 parts) were stirred together for19 hours at 70° C. until the Michael addition reaction was complete.This is Intermediate B.

Intermediate C

Jeffamine™ M600 (400.0 parts), 2-hydroxyethylacrylate (81.28 parts) and2,6-di-tert-butyl-4-methylphenol (0.06 parts) were stirred together for19 hours at 70° C. until the Michael addition reaction was complete.This is intermediate C.

Intermediate D

Tolylene diisocyanate (24.14 parts, 95%+2,4 isomer) was charged to astirred reaction vessel heated to 50° C. Poly(propylene glycol)monobutyl ether (127.95 parts, Mn 1200, ca. 0.77 mole equivalentsrelative to TDI) was charged to a dropping funnel and fed to thereaction mixture over 4 hours maintaining the temperature between 50-60°C. The reaction was then held at 70° C. for 60 minutes. Completereaction was determined by titration for residual isocyanate then thereaction mixture was cooled to 20° C. Diethanolamine (17.9 parts ca.1.59 mole equivalents based on TDI) was then added the reaction vesselheld at room temperature until no isocyanate remained as determined byinfrared analysis. The resulting mixture of products (which containedthe unwanted diadduct of diethanolamine with TDI) was dissolved indiethyl ether and purified by eluting down a column of silica. Thecolumn was washed three times with diethyl ether, the fractions combinedand solvent removed in vacuo to yield 90 parts of a solid product. Thisis Intermediate D. GPC analysis showed that the diadduct ofdiethanolamine with TDI had been removed.Intermediate E

1-Dodecanol (9.32 parts), ε-caprolactone (108.43 parts) andδ-valerolactone (35.04 parts) were stirred together under nitrogen at150° C. Zirconium butoxide catalyst (2.38 parts) was added and thereactants were stirred under nitrogen for 20 hours at 180° C. Aftercooling to 20° C., the polyester was obtained as a waxy solid. This ispolyester 2.

Tolylene diisocyanate (4.06 parts) was added to a stirred reactionvessel heated to 40° C. Polyester 2 (70.0 parts) dissolved in ethylacetate (70 parts) was added over 40 minutes with stirring at 50-54° C.The reaction was continued with stirring at ca. 50° C. for 120 minutes.The reactants were then cooled to 35° C. and diethanolamine (2.48 parts)was added followed by ethyl acetate (4.5 parts). The reaction wascontinued with stirring at 35° C. until no isocyanate remained. Theproduct was obtained as a milky dispersion in ethyl acetate. The solidscontent was determined as 50 wt % by gravimetric analysis. This isIntermediate E.

Intermediate F

The dihydroxy functional initiator

for use in atom transfer radical polymerisation was prepared accordingto the method described in ACS Symposium Series, New Orleans, 2000, 780,148-161. This is initiator 1.

N-(n-propyl)-2-pyridylethanimine was prepared according to the methoddescribed in Macromolecules 1999, 32, 2110-2119.

To a round bottom flask was charged copper bromide (0.87 parts) butylmethacrylate (30 parts), butyl acetate (30 parts) andN-(n-propyl)-2-pyridylethanimine (1.62 parts). The solution was purgedwith nitrogen and heated to 65° C. Initiator 1 was then added and thesolution held at 65° C. for 4 hours until the solids content reached 44wt %. The reaction was then cooled and diluted with tetrahydrofuran (60parts). Acidic alumina (20 parts) was then added to the solution andsuspended by agitation for 10 minutes. Solids were removed from theresulting mixture by filtration and basic alumina (20 parts) wassuspended in the filtrate passed for 10 minutes. The mixture wasfiltered and the majority of volatiles removed from the filtrate on arotary evaporator. The resultant poly(butyl methacrylate) was furtherdried in a vacuum oven. The product was characterised using sizeexclusion chromatography relative to polystyrene standards and hadMn=5300 and PDI (Polydispersity Index)=1.1. This is intermediate F.

Intermediate G

To a round bottom flask was charged copper bromide (0.43 parts) butylacrylate (30 parts) and pentamethylene diethylenetriamine (1.0 parts).The solution was purged with nitrogen and heated to 65° C. Initiator 1(1.44 parts) was then added and the solution held at 65° C. for 4 hoursuntil the solids content reached 90 wt %. Residual monomer was removedin vacuo. The resulting polybutyl acrylate was characterised using sizeexclusion chromatography with poly(methyl methacrylate) standards andhad Mn=5900 and PDI=1.1. This is intermediate G.

Intermediate H

A mono hydroxy initiator

was prepared by reacting ethylene glycol with 2-bromopropionyl bromideaccording to the general method described in ACS Symposium Series, NewOrleans, 2000, 780, 148-161. This is initiator 2.

To a round bottom flask was charged copper bromide (0.43 parts); butylacrylate (34 parts) and pentamethylene diethylenetriamine (1.0 parts).The solution was purged with nitrogen and heated to 80° C. Initiator 2(1.26 parts) was added and the solution held at 80° C. for 6 hours untilthe solids content reached 90%. Residual monomer was removed in vacuo.The resulting poly(butyl acrylate) was characterised using sizeexclusion chromatography relative to poly(methyl methacrylate) standardsand had Mn=4500 and PDI=1.1. This is intermediate H.

Intermediate I

Stearic acid (340 parts), 12-hydroxystearic acid (4205 parts) werestirred together under nitrogen at 100° C. Zirconium butoxide catalyst(23 parts) was added and the reactants were stirred under nitrogen for31 hours at 195° C. The reaction was cooled to 70° C. then ethanolaminewas added and the reaction held at 70° C. for 1 hr. The product washeated to 140° C. for 12 hrs until the acid value was less than 5mgKOH/g. The polyester was obtained as a waxy solid. This isIntermediate I.

Intermediate J

Stearic acid (495 parts), 12-hydroxystearic acid (7505 parts) werestirred together under nitrogen at 100° C. Zirconium butoxide catalyst(42 parts) was added and the reactants were stirred under nitrogen for31 hours at 195° C. The reaction was cooled to 70° C. thendiethanolamine was added and the reaction held at 70° C. for 1 hr. Theproduct was heated to 140° C. for 10 hrs until the acid value was lessthan 5 mgKOH/g. The polyester was obtained as a liquid. This isintermediate J.

Dispersants

Example 1 PU Dispersant with Polyether Side Chains

Dimethylpropionic acid (4.0 parts and often referred to as2,2-bis(hydroxymethyl)propionic acid), 1,4-cyclohexane dimethanol (7.25parts), polypropylene glycol monobutyl ether (8.86 parts, Mn 1000),Intermediate B (18.0 parts, Mn 2116) and methoxypropyl acetate (58.86parts) was stirred under nitrogen at 70° C. Dibutyltindilaurate (0.1parts) and isophorone diisocyanate (20.68 parts) were sequentially addedand the reactants were stirred under nitrogen for 3 hours at 70° C.until no isocyanate remained. This is Dispersant 1.

Example 2 PU Dispersant with Polyester Side Chains

1,6-Hexanediol (11.84 parts), Polyester 1 (17.81 parts, Mn 1600),Intermediate A (18.0 parts, Mn 1857) and methoxypropyl acetate (67.81parts) were stirred under nitrogen at 70° C. Tin (II) octanoate (0.09parts) was added followed by tolylene diisocyanate (20.09 parts). Thereactants were stirred under nitrogen for 3 hours until no isocyanateremained. This is Dispersant 2.

Example 3 PU Dispersant with Polyether Side Chains

1,4-Cyclohexane dimethanol (12.36 parts), Intermediate B (20.15 partsMn=2116) and methoxypropyl acetate (69.05 parts) were stirred undernitrogen at 70° C. Dibutyltindilaurate (0.08 parts) and tolylenediisocyanate (17.42 parts) were added and the reaction stirred undernitrogen for 2 hours. Jeffamine™ M2005 (19.05 parts) was then added andthe reactants stirred under nitrogen for 4 hours at 70° C. until noisocyanate remained. This is Dispersant 3.

Example 4

A dispersion was prepared by dissolving Dispersant 1 (0.25 parts) in asolution of nitrocellulose resin (1.16 parts) in a 5:1 mixture ofethanol and ethylacetate (6.09 parts). 3 mm Diameter glass beads (20parts) and carbon black pigment (Special Black 250 ex Degussa, 2.5parts) was added and milled on a horizontal shaker for 16 hours. Theresultant millbase exhibited excellent fluidity.

Example 5

A dispersion was prepared by dissolving Dispersant 2 (0.4 parts) in a5:1 mixture of methoxy propylacetate and n-butanol (8.1 parts). 3 mmDiameter glass beads (20 parts) and red pigment (1.5 parts,Chromaphthal™ Red A2B, ex Ciba) were added and the contents were milledon a horizontal shaker for 16 hours. The resultant millbase exhibitedexcellent fluidity.

Example 6

A dispersion was prepared by dissolving Dispersant 3 (1.0 parts) in a1.8:1 mixture of ethanol and ethyl acetate (7.0 parts). 3 mm Diameterglass beads (20 parts) and black pigment (2.0 parts, Printex™ 35, exDegussa) were added and the contents milled on a horizontal shaker for16 hours. The resultant millbase exhibited excellent fluidity.

Example 7

Intermediate B (35 parts) and ethyl acetate (59.30 parts) were stirredunder nitrogen at 50° C. Isophorone diisocyanate (3.68 parts) was addedand the reaction stirred under nitrogen for 10 minutes at 60° C.Dibutyltin dilaurate (0.08 parts) was added followed by isophoronediisocyanate (2.51 parts). The reaction mixture was held at 60° C. for10 minutes then Jeffamine™ M2005 (5 parts, ex Huntsman) was added. Thebatch was held at 60° C. for 10 minutes then m-xylenediamine was added(4.08 parts) followed by isophorone diisocyanate (4.66 parts). Thereaction mixture was held for a further 10 minutes then Jeffamine™ M2005(6.5 g, ex Huntsman) was added. The reaction was held at 70° C. for 3hours under nitrogen until no isocyanate remained. This is dispersant 7.

Example 8

1,4-Benzene dimethanol (12.58 parts), Intermediate B (88.2 parts),2,2-bis(hydroxymethyl)propionic acid (6.72 parts) and ethyl acetate(146.7 parts) were stirred under nitrogen at 70° C. Dibutyltin dilaurate(0.08 parts) was then added. Hexamethylene diisocyanate (32.29 parts)was dissolved in ethyl acetate (30 parts) and charged to the reactionmixture over 37 minutes. The reaction was held at 70° C. for 1 hour thenJeffamine™ M2005 (36.57 parts, ex Huntsman) was charged. The reactionmixture was stirred under nitrogen for a further 20 hours at 70° C.until no isocyanate remained. This is dispersant 8.

Example 9

1,4-Cyclohexanedimethanol (10.82 parts), Intermediate B (17.7 parts) andethyl acetate (66.69 parts) were stirred under nitrogen at 70° C.Dibutyltin dilaurate (0.08 pans) was then added.1,3-bis(1-isocyanato-1-methylethyl)-benzene (21.4 parts) was charged tothe reaction mixture over 15 minutes. The reaction was held at 70° C.for 1 hour then Jeffamine™ M2005 (16.69 parts, ex Huntsman) was charged.The reaction mixture was stirred under nitrogen for a further 2 hours at70° C. until no isocyanate remained. This is dispersant 9.

Example 10

Methylenedi-p-phenyldiisocyanate (46.38 parts) was charged to ethylacetate (54.24 parts) and heated to 63° C. under nitrogen. Dibutyltindilaurate (0.1 parts) was charged to the solution and poly(propyleneglycol) monobutyl ether (Mn 2500, 84.24 parts) was added over 30minutes. This is solution 1.

To a second vessel 1,4-Cyclohexanedimethanol (6.61 parts),2,2-bis(hydroxymethyl)propionic acid (9.66 parts), Intermediate B(107.10 parts) and ethyl acetate (200 parts) were charged and heated to70° C. with stirring under nitrogen. Dibutyltin dilaurate (0.1 parts)was added and then solution 1 was charged over 1 hour. The reaction washeld at 70° C. for 20 hours until no isocyanate remained. The productwas characterised using size exclusion chromatography relative topolystyrene) standards and had Mn=19,000 and PDI (PolydispersityIndex)=2.4. This is dispersant 10.

Example 11

1,4-Cyclohexanedimethanol (3.19 parts), intermediate B (34.5 parts),2,2-bis(hydroxymethyl)propionic acid (2.2 parts) and ethyl acetate(60.97 parts) were stirred under nitrogen at 70° C. Dibutyltin dilaurate(0.08 parts) was then added. Tolylene diisocyanate (10.03 parts chargedto the reaction mixture over 37 minutes. The reaction was held at 70° C.for 1 hour then Jeffamine™ M2005 (10.97 parts, ex Huntsman) was charged.The reaction mixture was stirred under nitrogen for a further 20 hoursat 70° C. until no isocyanate remained. The product was characterisedusing size exclusion chromatography relative to polystyrene) standardsand had Mn=10,900 and PDI (Polydispersity Index)=2.0. This is dispersant11.

Example 12

Tolylene diisocyanate (63.13 parts) was heated to 50° C. under nitrogen.Dibutyltin dilaurate (0.22 parts) was charged to the solution andpoly(propylene glycol) monobutyl ether (86.31 parts, Mn 2500) was addedover 30 minutes. This is solution 2.

To a second vessel 2,2-bis(hydroxymethyl)propionic acid (33.78 parts),Intermediate B (197.65 parts) and ethyl acetate (381.31 parts) werecharged and heated to 70° C. with stirring under nitrogen. Dibutyltindilaurate (0.22 parts) was added and then solution 2 was charged over 1hour. The reaction was held at 70° C. for 20 hours until no isocyanateremained. The product was characterised using size exclusionchromatography relative to polystyrene) standards and had Mn=11,100 andPDI (Polydispersity Index)=1.6. This is dispersant 12.

Example 13

1,4-Cyclohexanedimethanol (6.19 parts), intermediate B (58.65 parts),n-methyldiethanolamine (2.81 parts) and ethyl acetate (103.84 parts)were stirred under nitrogen at 70° C. Tolylene diisocyanate (4.83 parts)was charged followed by dibutyltin dilaurate (0.13 parts). Two furtheraliquots of tolylene diisocyanate were charged (3.61 parts and 8.79parts) and the reaction mixture held at 70° C. for 1 hour. Jeffamine™M2005 (18.84 parts, ex Huntsman) was then added. The reaction mixturewas stirred under nitrogen for a further 2 hours at 70° C. until noisocyanate remained. The product was characterised using size exclusionchromatography relative to polystyrene) standards and had Mn=14,200 andPDI (Polydispersity Index)=2.2. This is dispersant 13.

Example 14

Dispersant 13 (30 parts) as prepared and benzyl chloride (0.39 parts)were heated to 65° C. under nitrogen for 16 hrs. The reaction was cooledto room temperature. This is dispersant 14.

Example 15

Methylenedi-p-phenyldiisocyanate (50.46 parts) was charged to ethylacetate (100 parts) and heated to 64° C. under nitrogen. Dibutyltindilaurate (0.15 parts) was charged to the solution and poly(propyleneglycol) monobutyl ether (62.47 parts, Mn 1704) was added over 30minutes. This is solution 3.

To a second vessel n-methyldiethanolamine (14.24 parts), intermediate B(135 parts) and ethyl acetate (100 parts) were charged and heated to 70°C. with stirring under nitrogen. Dibutyltin dilaurate (0.15 parts) wasadded and then solution 3 was charged over 1 hour. Ethyl acetate (62.47parts) was then added. The reaction was held at 70° C. for 2 hours untilno isocyanate remained. The product was characterised using sizeexclusion chromatography relative to polystyrene) standards and hadMn=12,600 and PDI (Polydispersity Index)=3.0. This is dispersant 15.

Example 16

To dispersant 15 (397.41 parts) was added ethyl acetate (10.31 parts)and benzyl chloride (10.31 parts). The mixture was heated to 65° C.under nitrogen for 16 hrs. The reaction was cooled to room temperature.This is dispersant 16.

Example 17

1,4-Cyclohexanedimethanol (2.00 parts), intermediate B (34.50 parts),2,2-bis(hydroxymethyl)propionic acid (2.2 parts), n-phenyldiethanolamine(1.2 parts), and ethyl acetate (60.97 parts) were stirred under nitrogenat 70° C. Dibutyltin dilaurate (0.08 parts) was then added. Tolylenediisocyanate (10.03 parts) was charged to the reaction mixture over 30minutes. The reaction was held at 70° C. for 1 hour then Jeffamine™M2005 (10.97 parts, ex Huntsman) was charged. The reaction mixture wasstirred under nitrogen for a further 20 hours at 70° C. until noisocyanate remained. This is dispersant 17.

Example 18

Methylenedi-p-phenyldiisocyanate (42.96 parts) was charged to ethylacetate (110.0 parts) and heated to 71° C. under nitrogen. Dibutyltindilaurate (0.1 parts) was charged to the solution and poly(propyleneglycol) monobutyl ether (78.03 parts, Mn 2500) was added over 30minutes. This is solution 4.

To a second vessel 1,4-cyclohexanedimethanol (0.64 parts),poly(caprolactone diol) (12.83 parts, Mn 530),2,2-bis(hydroxymethyl)propionic acid (9.9 parts), intermediate B (113.40parts) and ethyl acetate (148.03 parts) were charged and heated to 70°C. with stirring under nitrogen. Dibutyltin dilaurate (0.17 parts) wasadded and then solution 4 was charged over 1 hour. The reaction was heldat 70° C. for 20 hours until no isocyanate remained. The product wascharacterised using size exclusion chromatography relative topolystyrene) standards and had Mn=12,100 and PDI (PolydispersityIndex)=2.4. This is dispersant 18.

Example 19

1,4-Cyclohexanedimethanol (10.22 parts), intermediate B (187.50 parts),2,2-bis(hydroxymethyl)propionic acid (9.63 parts) and ethyl acetate (200parts) were stirred under nitrogen at 70° C. Dibutyltin dilaurate (0.38parts) was then added. Tolylene diisocyanate (42.28 parts) in ethylacetate (40 parts) was charged to the reaction mixture over 30 minutes.The reaction was held at 70° C. for 1 hour then dibutylamine (2.99parts) in ethyl acetate (12.99 parts) was charged. The reaction mixturewas stirred under nitrogen for a further 20 hours at 70° C. until noisocyanate remained. This is dispersant 19.

Example 20

Methylenedi-p-phenyldiisocyanate (56.06 parts) was charged to ethylacetate (100.0 parts) and heated to 70° C. with stirring under nitrogen.Dibutyltin dilaurate (0.12 parts) was charged to the solution andpoly(propylene glycol) monobutyl ether (146.09 parts, Mn 2500) was addedover 30 minutes. This is solution 5.

To a second vessel 1,4-cyclohexanedimethanol (9.94 parts),2,2-bis(hydroxymethyl)propionic acid (11.68 parts), intermediate B(82.08 parts) and ethyl acetate (150 parts) were charged and heated to70° C. with stirring under nitrogen. Dibutyltin dilaurate (0.12 parts)was added and then solution 5 was charged over 1 hour. Ethyl acetate(56.9 parts) was charged to the reaction mixture. The reaction was heldat 70° C. for 20 hours until no isocyanate remained. The product wascharacterised using size exclusion chromatography relative topolystyrene) standards and had Mn=10,200 and PDI (PolydispersityIndex)=2.3. This is dispersant 20.

Example 21

Methylenedi-p-phenyldiisocyanate (53.80 parts) was charged to ethylacetate (120 parts) and heated to 70° C. with stirring under nitrogen.Dibutyltin dilaurate (0.15 parts) was charged to the solution andpoly(propylene glycol) monobutyl ether (97.72 parts, Mn 2500) was addedover 30 minutes. This is solution 6.

To a second vessel 1,4-cyclohexanedimethanol (8.54 parts),2,2-bis(hydroxymethyl)butyric acid (11.36 parts), intermediate B (126.00parts) and ethyl acetate (177.72 parts) were charged and heated to 70°C. with stirring under nitrogen. Dibutyltin dilaurate (0.15 parts) wasadded and then solution 1 was charged over 1 hour. The reaction was heldat 70° C. for 20 hours until no isocyanate remained. The product wascharacterised using size exclusion chromatography relative topolystyrene) standards and had Mn=12,000 and PDI (PolydispersityIndex)=2.4. This is dispersant 21.

Example 22

1,4-Cyclohexanedimethanol (5.12 parts), intermediate D (25.20 parts),and ethyl acetate (50.52 parts) were stirred under nitrogen at 70° C.Dibutyltin dilaurate (0.08 parts) was then added. Tolylene diisocyanate(9.62 parts) was charged to the reaction mixture over 30 minutes in fouraliquots. The reaction was held at 70° C. for 1 hour then Jeffamine™2005 (10.52 parts, ex Huntsman) was added. The reaction mixture wasstirred under nitrogen for a further 2 hours at 70° C. until noisocyanate remained. This is dispersant 22.

Example 23

1,4-Cyclohexanedimethanol (3.17 parts), intermediate C (34.00 parts),and ethyl acetate (54.18 parts) were stirred under nitrogen at 70° C.Dibutyltin dilaurate (0.08 parts) was then added. Tolylene diisocyanate(12.75 parts) was charged to the reaction mixture over 30 minutes infour aliquots. The reaction was held at 70° C. for 1 hour thenJeffamine™ 600 (4.18 parts, ex Huntsman) was added. The reaction mixturewas stirred under nitrogen for a further 2 hours at 70° C. until noisocyanate remained. This is dispersant 23.

Example 24

Dispersions were prepared by dissolving each of the dispersants 7-23(1.0 parts) in a 3:1 mixture of ethanol and ethyl acetate (7.0 parts).Glass beads (3 mm diameter, 20 parts) and black pigment (2.0 parts,Printex™ 35, ex Degussa) were added and the contents milled on ahorizontal shaker for 16 hours. The resultant millbases exhibitedexcellent fluidity. A comparative control dispersion was preparedwithout a dispersant i.e. a mixture of a 3:1 mixture of ethanol andethyl acetate (8.0 parts), glass beads (3 mm diameter, 20 parts) andblack pigment (2.0 parts, Printex™ 35, ex Degussa) were milled on ahorizontal shaker for 16 hours. The resulting dispersion was highlyviscous with the characteristics of a gel.

The millbases (1.0 parts) were let down into (a) a polyurethane resin,NeoRez™ U395 (3.0 parts, ex NeoResins), and (b) a nitrocellulose resin,NC DLX ⅗, (3.0 parts, ex Nobel Enterprises) and the resulting inks drawndown on to black and white card using a number 3 K-bar. A simple visualassessment was made of the drawdowns based on hiding power, jetness andgloss with a scoring system of 1 to 5. A score of 5 indicates the bestperformance. A control experiment with no dispersant gave a let downwith quality equal to 1.

Score for let down Score for let down Dispersant into polyurethane intonitrocellulose none 1 1 7 5 4 8 4 3 9 3 3 10 4 5 11 5 4 12 4 5 13 4 3 145 5 15 4 4 16 5 5 17 4 5 18 4 5 19 4 4/3 20 3 4 21 4 5 22 4 5 23 3 3

Example 25

1,4-Cyclohexanedimethanol (5.19 parts), Intermediate B (22.50 parts),Intermediate A (25 parts) and ethyl acetate (22.5 parts) were stirredunder nitrogen at 70° C. Dibutyltin dilaurate (0.075 parts) was thenadded. Tolylene diisocyanate (9.74 parts) in ethyl acetate (10 parts)was charged to the reaction mixture over 30 minutes. The reaction washeld at 70° C. for 1 hour then polyester 1 (8.52 parts) in ethyl acetate(13.52 parts) was charged. The reaction mixture was stirred undernitrogen for a further 20 hours at 70° C. until no isocyanate remained.This is dispersant 25.

Example 26

1,4-Cyclohexanedimethanol (6.29 parts), Intermediate A (65 parts) andethyl acetate (7.24 parts) were stirred under nitrogen at 70° C.Dibutyltin dilaurate (0.075 parts) was then added. Tolylene diisocyanate(11.14 parts) in ethyl acetate (10 parts) was charged to the reactionmixture over 30 minutes. The reaction was held at 70° C. for 1 hour thenPolyester 1 (9.74 parts) in ethyl acetate (12.00 parts) was charged. Thereaction mixture was stirred under nitrogen for a further 20 hours at70° C. until no isocyanate remained. This is dispersant 26.

Example 27

Hexanediol (1.26 parts), Intermediate A (13.20 parts),n-methyldiethanolamine (1.58 parts), polyester 1 (9.90 parts),dibutyltin dilaurate (0.03 parts) and ethyl acetate (30.32 parts) werestirred under nitrogen at 70° C. Tolylene diisocyanate (5.93 parts) wascharged over 15 minutes and the reaction mixture held at 70° C. for 20hours until no isocyanate remained. This is dispersant 27.

Example 28

To dispersant 28 (30 parts) was added ethyl acetate (0.71 parts) andbenzyl chloride (0.71 parts) were heated to 65° C. under nitrogen for 16hrs. The reaction was cooled to room temperature. This is dispersant 28.

Example 29

Hexanediol (0.62 parts), Intermediate A (6.00 parts),2,2-bis(hydroxymethyl)propionic acid (0.72 parts), polyester 1 (4.42parts), dibutyltin dilaurate (0.02 parts) and ethyl acetate (13.70parts) were stirred under nitrogen at 70° C. Tolylene diisocyanate (2.64parts) was charged over 15 minutes and the reaction mixture held at 70°C. for 20 hours until no isocyanate remained. This is dispersant 29.

Example 30

Hexanediol (4.86 parts), Intermediate E (7.20 parts), polyester 2 (12.98parts), dibutyltin dilaurate (0.03 parts) and ethyl acetate (32.98parts) were stirred under nitrogen at 70° C. Tolylene diisocyanate (7.91parts) was charged over 15 minutes and the reaction mixture held at 70°C. for 20 hours until no isocyanate remained. This is dispersant 30.

Example 31

Hexanediol (7.34 parts), Intermediate F (10.8 parts), and methoxypropylacetate (40.47 parts) were stirred under nitrogen at 70° C. octanoate(0.05 parts) was then added. Tolylene diisocyanate (11.81 parts) wascharged to the reaction mixture over 30 minutes in four aliquots. Thereaction was held at 70° C. for 1 hour then polyester 1 (10.47 parts)was added. The reaction mixture was stirred under nitrogen for a further2 hours at 70° C. until no isocyanate remained. This is dispersant 31.

Example 32

Hexanediol (5.21 parts), Intermediate G (11.25 parts), and methoxypropyl acetate (32.54 parts) were stirred under nitrogen at 70° C.Tin(II) octanoate (0.05 parts) was then added. Tolylene diisocyanate(8.5 parts) was charged to the reaction mixture over 30 minutes in fouraliquots. The reaction was held at 70° C. for 1 hour then polyester 1(7.54 parts) was added. The reaction mixture was stirred under nitrogenfor a further 2 hours at 70° C. until no isocyanate remained. This isdispersant 32.

Example 33

Hexanediol (4.44 parts), Intermediate G (6.13 parts), and methoxypropylacetate (24.50 parts) were stirred under nitrogen at 70° C. Tin(II)octanoate (0.03 parts) was then added. Tolylene diisocyanate (6.91parts) was charged to the reaction mixture over 30 minutes in fouraliquots. The reaction was held at 70° C. for 1 hour then Intermediate H(7.00 parts) was added. The reaction mixture was stirred under nitrogenfor a further 2 hours at 70° C. until no isocyanate remained. This isdispersant 33.

Example 34

Dispersions were prepared by dissolving each of the Dispersants 25-33(0.4 parts) in a 5:1 mixture of methoxypropyl acetate and n-butanol (8.1parts). 3 mm Diameter glass beads (20 parts) and red pigment (1.5 parts,Chromaphthal™ Red A2B, ex Ciba) were added and the contents were milledon a horizontal shaker for 16 hours. The resultant mill bases exhibitedfluidity as described in the following table.

Dispersant Fluidity of millbase None (Control) Immovable gel 25Excellent fluidity 26 Excellent fluidity 27 Fluid, gels on standing 28Excellent fluidity 29 Fluid, gels on standing 30 Excellent fluidity 31Excellent fluidity 32 Excellent fluidity 33 Excellent fluidity

Example 35

A dispersion was prepared by dissolving Dispersant 11 (3.5 parts) inMacrynal™ SM565 (1.05 parts, commercially available from SurfaceSpecialties UCB) and methoxypropyl acetate (24.50 parts). 3 mm Diameterglass beads (125 parts) and red pigment (5.95 parts, Irgaphor™ red B-CFex Ciba) were added and the contents were milled on a skandex shaker for1 hour. The resultant mill base exhibited excellent fluidity. The millbase viscosity remained below 0.1 Pa·s as the shear rate was increasedfrom 38.6 to 2391.1 s⁻¹.

The resulting Mill base was let down into Macrynal™ SM565/70BAC (24.45parts), Desmodur™ N3390 (2.2 parts) and methoxypropyl acetate (17.68parts) then drawn down onto black and white card using a number 3 K-bar.The resulting surface maintained high gloss values 95.7 (60° angle) and58.6 (20° angle).

Example 36

A dispersion was prepared by dissolving each of the dispersants 10, 11or 18 in Macrynal™ SM565 (1.05 parts) and propylene glycol methyl ether(21.40 parts) 3 mm glass beads (125 parts) and blue pigment (8.75 parts,Heliogen™ Blue L6700F ex Bayer) were added. The resultant mill basesexhibited excellent fluidity

The mill bases were let down into Macrynal™ SM565/70BAC (36.36 parts),Desmodur™ N3390 (3.24 parts, ex Bayer) and methoxypropyl acetate (39.02parts) then drawn down onto black and white card using a number 3 K-bar.The resulting surface maintained high gloss values.

Mill base Viscosity at a Gloss Gloss Dispersant shear rate of 37.6 s⁻¹60° C. 20° C. Haze 10 1.857 80.0 48.7 337 11 0.938 81.9 56.9 247 181.296 82.9 56.7 282

Example 37

1,4-Cyclohexanedimethanol (13.88 parts), intermediate I (40.16 parts),Intermediate J (60 parts) and toluene (140.16 parts) were stirred undernitrogen at 75° C. Dibutyltin dilaurate (0.15 parts) was then added.Tolylene diisocyanate (25.97 parts) was charged to the reaction mixtureover 100 minutes. The reaction was stirred under nitrogen for a further22 hours at 75° C. until no isocyanate remained.

Example 38

A dispersion was prepared by dissolving Dispersant 37 (1.0 parts) intoluene (7 parts). 3 mm Diameter glass beads (20 parts) and red pigment(2.0 parts, Chromaphthal™ Red A2B, ex Ciba) were added and the contentswere milled on a horizontal shaker for 16 hours. The resultant mill baseexhibited excellent fluidity.

Each of the documents referred to above is incorporated herein byreference. Except in the Examples, or where otherwise explicitlyindicated, all numerical quantities in this description specifyingamounts of materials, reaction conditions, molecular weights, number ofcarbon atoms, and the like, are to be understood as modified by the word“about.” Unless otherwise indicated, each chemical or compositionreferred to herein should be interpreted as being a commercial gradematerial which may contain the isomers, by-products, derivatives, andother such materials which are normally understood to be present in thecommercial grade. However, the amount of each chemical component ispresented exclusive of any solvent or diluent oil, which may becustomarily present in the commercial material, unless otherwiseindicated. It is to be understood that the upper and lower amount,range, and ratio limits set forth herein may be independently combined.Similarly, the ranges and amounts for each element of the invention maybe used together with ranges or amounts for any of the other elements.As used herein, the expression “consisting essentially of” permits theinclusion of substances that do not materially affect the basic andnovel characteristics of the composition under consideration.

The invention claimed is:
 1. A non-aqueous composition comprising aparticulate solid, an organic medium and a polyurethane dispersanthaving laterally attached solvent-solubilising side chains of polyetherchain, wherein the polyether chain is poly(C₂₋₄-alkylene oxide)containing less than 60% by weight ethylene oxide, wherein thenumber-average molecular weight of the polyether side chain is from 300to 10,000 and being the residue of a polyether which contained a) onehydroxyl and one secondary amino group at one end of the polyether chainwhich reacts with isocyanates or b) two hydroxyl groups at one end ofthe polyether chain which react with isocyanates and which are separatedby not less than 5 atoms and wherein the polyurethane dispersant isderived from isocyanates having a functionality from 2.0 to 2.1.
 2. Thecomposition as claimed in claim 1 wherein the polyether side chaincontains a terminating C₁₋₅₀-hydrocarbyl group.
 3. The composition ofclaim 1 wherein the polyurethane dispersant additionally comprises from10 to 180 milliequivalents for each 100 g dispersant of an acid and/oramino group.
 4. The composition of claim 1 wherein the polyurethanedispersant further comprises the residue of a formative compound havinga number average molecular weight of from 32 to 3,000.
 5. Thecomposition of claim 1 wherein the total weight percentage ofsolvent-solubilising lateral side chains is not less than 5% based onthe total weight.
 6. The composition of claim 1 wherein the polyurethanedispersant is obtainable or obtained from a diisocyanate.
 7. Thecomposition of claim 1 wherein the solvent-solubilising polyether chaincontains the residue of a compound of formula 1

wherein R is C₁₋₂₀-hydrocarbyl group; R¹ is hydrogen, methyl or ethyl ofwhich less than 60% is hydrogen; R² and R³ are each, independently,C₁₋₈-hydroxyalkyl; Z is C₂₋₄-alkylene; X is —O— or —NH—; Y is theresidue of a polyisocyanate; m is from 5 to 150; p is from 1 to 4; and qis 1 or
 2. 8. The composition of claim 1 wherein the solventsolubilising polyether chain contains the residue of a compound offormula 2

wherein R is C₁₋₂₀-hydrocarbyl group; R¹ is hydrogen, methyl or ethyl ofwhich less than 60% is hydrogen; R⁴ is an isocyanate reactive organicradical; R⁵ is hydrogen or an isocyanate-reactive organic radical; Z isC₂₋₄-alkylene m is from 5 to 150; and n is 0 to
 1. 9. The composition ofclaim 1 wherein the solvent-solubilising polyether chain contains theresidue of a compound of formula 3

wherein R is C₁₋₂₀-hydrocarbyl group; R¹ is hydrogen, methyl or ethyl ofwhich less than 60% is hydrogen; W is C₂₋₆-alkylene; and m is from 5 to150.
 10. A polyurethane dispersant having laterally attachedsolvent-solubilising polyether chains of poly(C₂₋₄-alkylene oxide) whichcontains less than 60% by weight ethylene oxide relative to thepoly(C₂₋₄-alkylene oxide) chain, wherein the number-average molecularweight of the polyether side chain is from 300 to 10,000 and being theresidue of a polyether which contained a) one hydroxyl and one secondaryamino group at one end of the polyether chain which reacts withisocyanates or b) two hydroxyl groups at one end of the polyether chainwhich react with isocyanates and which are separated by not less than 5atoms and wherein the polyurethane dispersant is derived fromisocyanates having a functionality from 2.0 to 2.1.
 11. The polyurethanedispersant of claim 10 wherein the poly(C₂₋₄-alkylene oxide) chain isthe residue of a polyether which contains one hydroxyl and one secondaryamino group at one end of the polyether chain which reacts withisocyanates.
 12. The polyurethane dispersant of claim 10 wherein thepoly(C₂₋₄-alkylene oxide) chain is the residue of a polyether whichcontains two hydroxyl groups at one end of the polyether chain whichreact with isocyanates and which are separated by not less than 5 atoms.13. The polyurethane dispersant of claim 10 which further comprises from10 to 180 milliequivalents of an acid or amino group, including saltsthereof for each 100 g dispersant.
 14. A non-aqueous millbase, paint orink which comprises a film-forming resin and the composition of claim 1.